Chiang Mai Weather in September
Typical weather, rainfall, and packing tips for Chiang Mai in September
Thailand · September
Chiang Mai Weather in September
September weather in Chiang Mai averages 29°C with 12 rain days and 78% humidity. Rains easing.
Daytime high
32°C
Nighttime low
25°C
Rain days
12 days
UV index
9
When to visit Chiang Mai?
● Great·● Okay·● Avoid
Typical Weather in Chiang Mai in September
Based on 30-year historical averages.
Temperature
Conditions
What to Expect in September
- 1Daytime highs around 32°C, dropping to 25°C at night.
- 2Expect 12 rain days — pack a waterproof jacket.
- 3Humidity sits at 78% — quite humid.
- 46 hours of sunshine per day on average.
- 5UV index of 9 — use SPF 50+.
What to Pack for Chiang Mai in September
Best Activities for September Weather
Outdoor sightseeing
Plan outdoor activities for mornings when temperatures are most comfortable.
Indoor attractions
With 12 rain days, museums and covered markets are great backup plans.
Food and culture
Autumn seasonal dishes and local festivals make September culturally rich.
.png)
Build a personalised itinerary, your way
Drag and drop destinations, activities, and stays into your perfect day-by-day plan. Reorder stops, adjust timing, and share your itinerary with travel companions in one place.
Your whole trip,
in your pocket.
Every day, every stay, every transfer lives in the app. Pull up your canvas on the go, track where you are day by day, and never lose the thread of your trip.
Frequently Asked Questions
How we work this out
Temperature and rainfall figures are 30-year meteorological averages. Crowd levels come from national tourism arrival data. Price bands reflect mid-range accommodation and economy flights from major long-haul cities, sampled quarterly.
Last updated 18 July 2026 · Written by the Holicay travel team